Incinerator



Oct. 19, 1965 H. J. CATES, JR., ETAL 3,212,465

INCINERATOR l0 Sheets-Sheet 1 Filed Sept. 14. 1960 INVENTORS GATES JR.ROSENBERG .ATTORN v HENRY J a? Oct. 19, 1965 H. .1. CATES, JR., ETALINCINERATOR l0 Sheets-Sheet 2 Filed Sept. 14. 1960 I a I INVENTOR. HENRYJ. CATES JR. BYTOM ROSENBERG Oct. 19, 1965 H. J. CATES, JR.. ETAL3,212,465

INCINERATOR Filed Sept. 14. 1960 10 Sheets-Sheet 5 ROS ENBER G mix/14%ATT NEY "r mom m2 x3 9 n w: n: we a m u u w .M w n @c u. o: a w

Oct. 19, 1965 H. J. CATES, JR, ETAL 3,212,465

INGINERATOR Filed Sept. 14. 1960 10 Sheets-Sheet 6 INVENTOR.

HENRY J. GATES JR YTOM RosENBEhs INCINERATOR l0 Sheets-Sheet '7 FiledSept. 14, 1960 mmm INVENTORS HENRY J. BYTOM ROSENBE s ,m/M/

CATES,JR.

ATTO EY Oct. 19, 1965 H. J. CATES, JR., ETAL 3,21

INGINERATQR 1O Sheets-Sheet 9 Filed Sept. 14. 1960 IN VENTORS 35?. YR 6seiq e e ,jam J ATTOR Y H. J. GATES, JR., ETAL 3,212,465

Oct. 19, 1965 INGINERATOR 1O Sheets-Sheet 10 Filed Sept. 14. 1960INVENTORS J CATE s ,JR

ROSENBERG AT TOR Y United States Patent 3,212,465 INCINERATOR Henry J.Cates, Jr., De Kalb County, and Tom Rosenberg, las; Point, Ga. (Both of416 Walton Bldg., Atlanta 3,

Filed Sept. 14, 1960, Ser. No. 56,015 14 Claims. (Cl. 11038) Thisinvention relates to an incinerator and particularly to an incineratorof the continuous feeding and continuous operating type which isemployed to burn refuse and to the method and apparatus employed in theincinerator arrangement using air and heat for continuously burning bothwet and dry material in order to reduce it to a very fine ash which mayreadily be disposed of for various uses.

The characteristics of refuse is varied. It is often difficult tocalculate the combustion characteristics of refuse, since refuse is ageneric term usually meaning solid or semisolid materials whichoriginate as by-products of industry or as waste from domestic orcommercial activities. Combustible refuse consists of such common,organic compounds as grass, tree trimmings, paper, cartons, woods,straw, carpets, rags, rubber, plastics, fats, oils, petroleum productsand similar wastes. Chemically, this refuse is composed mostly ofcellulose and lignin and in some sections of the United States,combustible refuse also includes incompletely burned ashes of such hardfuels as coal and charcoal. Similarly, garbage, mixed with other refuse,is often successfully disposed of in well operated incinerators,provided the fuel value of the total mixture is maintained at asufiicient level. The molecules of each of these different compoundscontain a specific proportion of carbon and hydrogen and the mainsources of heat energy are represented by the carbon and hydrogen.

Among the many problems inherent in incinerating large quantities ofrefuse are the following:

(1) The control of hot gases within the interior of the plant and theutilization of them for pro-drying operation and other uses involvesmatters of air flow, hotter versus cooler gas flows, and other similarprinciples.

(2) The maintaining of temperatures within the chambers of the plantmust be so that the operation may be uniform and so that the heat thatis produced from the burning can be readily and directly used in theprocess.

(3) The matter of incomplete combustion, which is inevitable at times,and also the elimination of a large amount of unburned refuse.

(4) Difficulties in design and the use of test components so thatmaintenance and repairs can be performed very easily. There must beaccess to various parts and those parts which Wear or deteriorate mustbe replaced while the plant is in operation.

(5) Various by-products are produced in the process of incineration anddestruction of mixture of materials which provides a residue and ash,various scrap metals that are not consumed, and other materials whichmust be removed.

There are several methods in this country for disposing of refuse whichincludes garbage and other types of waste materials normally picked upfrom residences and commercial establishments. There is one primarydifference between the refuse and waste material from the residences ofthe United States which is contrasted with that of other countries,particularly the European countries: The fact that garbage and refuse inthe former is very much on the dry side because of the high bulk of drypaper and other materials, whereas the latter is more of the wet typegarbage which is more difiicult to burn, but at the same time is easierto control at its burning. The use of all) 'ice

kitchen garbage disposal units in the American home contributes to theelimination of some of the wet material from the refuse which causes therefuse to be even more on the dry side with a good bit less moisture.Therefore, any domestic incinerator operation which takes refuse fromthe residences and reduces it to a fine ash must take into considerationin its operation the burning of a good bit of highly combustible andhighly burnable material and the absence of some of the moisture whichhas been present in other types of garbage. All of these continuousincinerators operate on the principle of collecting the garbage at onecentral point near the entrance to the incinerator and then picking upthe garbage by large cranes or trucks or in some other manner andfeeding it into the entrance into the incinerator in a continuous,straight line pattern, keeping a constant supply of refuse flowing intothe entrance into the incinerator. This material must be pro-dried to acertain moisture content in order to control the process and in order toreduce the material in the proper manner to the desired ash at the endof the process.

The present invention relates to an over-all improvement in the methodand apparatus employed in refuse incinerators. The instant methodsemploy the continuous feeding of the refuse and the pre-drying thereofwith further tumbling and conveying of the material through ignitiongrates where about one-half of the burning takes place. Hot gasesproduced from the burning on the ignition grates are diverted back intothe refuse entering the material on the pre-drying grates. The refuseitself is passed from the ignition grates into a rotary kiln where it istumbled, by which action the refuse is agitated in such a manner whichenables it to be completely destroyed. At the end of the rotary kiln,the small ash is spilled into a residue conveyor and removed from thescene, either by trucks or by any other suitable method.

Generally described, the incinerator is a continuously operated andcontinuously fed apparatus adapted to burn mixed refuse continuously asit is fed. The various incinerator units as sub-combinations are: thefeed chute; the pre-drying or simple drying grates, whereat the refuseis spread and dried to some extent; the ignition grates, at which pointthe refuse is actually burned or ignited and partially destroyed byburning; the water seal chamber, by which hot ash is quenched and moved;the rotary kiln, at which place the remainder of the refuse from theignition grates is tumbled and burned to an ash; and the mixing chamber.The method employed is that of mixing the refuse in the collection ordepository area, then feeding the material on todrying grates, whichspread the material, and at the same time introducing hot air or gasesacross the material to evaporate some of the moisture therefrom. Themethod then encompasses transferring the material into an ignitionchamber in which there is located a particular arrangement of ignitiongrates adapted to spred the refuse across the length thereof and toignite and burn it as it moves. From the ignition grates, the materialis rotated and completely burned in a rotary kiln which produces gasesthat are employed in the method in the mixing chamber.

All of the individual elements or apparatus of the present system areplaced together in one composite arrangement inside a building structureand are inter-related in a continuously fed and continuously burningoperation connected by suitable pasageways and duct work properly sealedand joined to provide a composite and continuous method and apparatus ofincinerating refuse from the beginning with the partially wet refuse tothe end where there is a fine ash. Generally described, the apparatusconsists of a feed chute arrangement employing a sand seal and a reversetaper and a particular arrangement of air seal; drying grates upon whichthe refuse is fed and partially dried and which grates compriselongitudinal stringers, alternate sections driven by a rocker armassembly employing wear pads and replaceable grate bars, together with aspecial air or water cooled beam and a reinjection conveyor system whichremoves and conveys the siftings from under the drying grates anddischarges it back into the furnaces for burning; a by-pass arrangementwhich removes odoriferous gases by a special baflle aircooled arch inthe ignition grate chamber; ignition grates which employ a number ofnovel and useful elements, including individual shearpin arrangement,seal arrangement on the pressure arms, alternate reciprocatinglongitudinal stringers, wear shoes and hold-down assemblies or rockerarm assemblies, the rotary kiln in which the refuse is finally burned toa fine ash which includes such worthwhile arrangements as a kiln seal, aspring plate mounted girth gear, water cooled trunnions and a segmentedkiln discharge casting; and a mixing chamber.

In a preferred embodiment, the ignition grates are designed to burnabout half the rated capacity, providing heat for the drying grates, andalso for the burning operation in the rotary kiln. The rotary kiln shallcompletely consume the balance of the refuse and the moisture ladengases from the drying grates by-pass the rotary kiln and are reheated inthe mixing chamber to control the odor thereof. The preferred unit iscapable of operating entirely without manual stoking and produces afine, completely consumed residue which can be processed to reclaimmetals and useful lay-products.

The operation of the instant method and apparatus is as follows:

First, garbage and refuse is delivered by collection trucks into astorage pit. This allows cranes to select and mix refuse to assist increating the best burning condition in the furnace.

The refuse is hoisted from the storage pit by cranes with grab bucketsto a feed hopper. From the dumping pit to feed hopper, the process isintermittent, but from the hopper to the final loading of residue ontothe trucks for disposal, it is a continuous process.

From the hopper, garbage and refuse is fed into a pre-drying chamberwhere drying is done by radiation from the ignition chamber, below andafter the drying chamber. A portion of the hot gases from the ignitionchamber rises and passes over the wet garbage and refuse. Then they areconducted to the combustion chamber by a separate by-pass duct over therotary kiln. From the drying chamber, refuse moves into the ignitionchamber by means of mechanically operated grates, the speed of which canbe varied to suit desired rates of combustion. Pro-heated air is thenintroduced beneath the fuel bed or the ignition grates. This pre-heatedair is controlled by the operator to meet the requirements ofcombustion. The air pre-heater may be built into and to form a part ofthe furnace sidewalls.

By means of the mechanically operated grates, the partly consumed andburning garbage and refuse is fed into a slowly revolving, inclinedkiln, the speed of which may be varied to suit the desired conditions.The slow cascading passage through the kiln exposes unburned refusecontinuously to hot gases from the ignition grates and completesincineration. Hot gases from the kiln pass into a mixing chamber, w herethey unite with gases from the drying and ignition chambers. Herecombustion of all gases is completed before they proceed to the stack,or boilers. Simultaneously, from the dumping zone of the kiln, residueis placed onto a slow moving conveyor which is submerged in water. Thisthoroughly quenches the residue as it is carried outside to a processingpoint Where metals can be removed and the remaining residue can then behauled away by trucks for use as a sub-base for streets, parking lots orpermanent fills. From the time it enters the feed chute until it isdumped as residue, the refuse and garbage is in continuous motion. Thus,it cannot form'huge clinkers but remains in comparatively small, denseparticles, thereby producing a residue which is ideal for road building,sub-grade or land fills. Panel boards are provided for complete controlof every stage of the process and on them are mounted pyrometers, draftgages, electronic control-s for motors, smoke recorders and otheroperating controls.

In the ensuing descriptive material, the over-all method and thecomplete apparatus is shown and described both in diagrammatic viewswhich are diagrams of a complete plant shown by a section viewtherethrough and in other views which show sub-elements and theirdetails.

A primary object of this invention is to provide a method ofincineration which continuously disposes of large amounts of refuse, andwhich reduces it to a fine size and small quantity which can be removedfrom the system.

Another object of this invention resides in the particular arrangementof the component chambers and parts of the plant, whereby gases producedin the combustion of the materials may be utilized to best advantage andwhereby various pressure differentials may be controlled for the bestoperation of the system.

Another advantage of this system resides in the various component partsthereof, including the chambers in which pre-drying and combustion andcomplete drying take place, as well as the pre-drying grates, theignition grates, the rotary kiln and other portions of the over-allsystem.

An additional object of this invention may be found in the arrangementof the movable and stationary grates and mechanical structure associatedtherewith, which provides a particularly advantageous type of dryinggrate.

Still another advantage of this invention is found in the ignitiongrates, wherein the major ignition of the refuse takes place andincluding such novel and worthwhile things as the individual shearpinarrangement, the movable and stationary ignition grates, the wear shoeand rocker arm support arrangement and other features of this particularportion.

In the ensuing drawings and description, reference is made from time totime to various elements of the overall method and apparatus. Followinga description of the method employed and the apparatus as a whole, thereare specific numerals assigned to represent a particular portion of thesystem and a special part of the specification is used to describe thesevarious subcombinations in detail. All of the numerals of a certaingroup, for example, will begin with the same digit so that the parts mayreadily be identified with respect to which element they belong.Preliminary to this, it is pointed out that the ignition grates receivethe refuse from the drying grates, and, therefore, reference is madefrom time to time to drying grates and ignition grates and it is to beunderstood that these are not the same grates. Furthermore, both theignition and drying grates employ movable and stationary grates. Thedrying grates are mounted within a specific area which is generallyknown as the drying chamber and the ignition grates are mounted withinan area of the plant which is referred to as the ignition chamber andwhile these chambers are open to one another and connected by variousheat and air ducts, it is to be understood that they refer to theparticular chamber in which these particular elements are located. Thecomplete system, method, apparatus and various sub-combinations areeasily adapted to be contained within a special plant or building havingan exterior resembling a building structure of whatever materials andwith whatever ornamentation and originality is desired and for allpractical purposes, the system may be considered a continuous operatingplant which is housed in a building structure having variouscompartments and chambers connected'together to direct the refuse fromits original state at the beginning until it is burned to a fine ash atthe end.

With respect to my previous mention of chambers within the plant, it ispointed out that the movement of refuse during the process from onechamber to another presents a particular problem since it is necessaryto join such chambers by some means sealing the gases and heat fromother portions of the plant. One particularly novel thing in myinvention is found in the air seal between the open feed chute and thedrying chamber employing a sand seal between the feed chute and areverse taper on the feed chute to provide easy passage of the refuse toprevent blocking of the chute.

Other and further objects and advantages of my invention will becomeapparent from the following description taken in conjunction with theaccompanying drawings, wherein:

FIG. 1 is a vertical cross-sectional view through a typical plant usingthe method and apparatus of the present invention with the air and gasfiow shown by light lines with arrowheads thereon.

FIG. 2 is a front perspective view of the drying grates contained withinthe drying grate compartment below the feed chute in FIG. 1.

FIG. 3 is a longitudinal cross-sectional view through a movable gratetaken substantially along line 33 in FIG. 2.

FIG. 4 is a cross sectional view through one movable grate takensubstantially along line P4 in FIG. 3 and with parts removed.

FIG. 5 is a cross-sectional view taken substantially along line 5-5 inFIG. 3.

FIG. 6 is an end view of one stationary grate taken substantially alongline 6-6 in FIG. 3 and with parts broken away.

FIG. 7 is a top plan view of the air cooled beam which supports thelower end of the grates in FIG. 2.

FIG. 8 is a front elevation view of the beam shown in FIG. 7.

FIG. 9 is a cross-sectional view taken substantially along line 9-9 inFIG. 8.

FIG. 10 is a perspective view of the ignition grate assembly.

FIG. 11 is a rear elevation view of the rear drive portion for theignition grates.

FIG. 12 is a side elevation view of the ignition grate assembly shown inFIG. 10 with one side of the duct removed to expose the grates.

FIG. 13 is a cross-sectional view taken substantially along line 13-13in FIG. 12.

FIG. 14 is a cross-sectional view of the ignition grate dischargecasting taken substantially along line 14-14 in FIG. 10.

FIG. 15 is a side elevation view of one of the ignition grate sidewallcastings.

FIG. 16 is a cross-sectional view of the ignition grate sidewall castingtaken substantially along line 1616 in FIG. 15.

FIG. 17 is a vertical cross-sectional view through a modified form ofthe ignition grate movable stringers showing the modified wear supporttherefor.

FIG. 18 is an enlarged detail rear elevation view of one of the wearsupports shown in FIG. 17, tilted out of normal vertical position by astraight line projection from the left side of FIG. 19.

FIG. 19 is a cross-sectional view taken along the line 19-19 in FIG. 18.

Referring initially to FIG. 1 of the drawings for a description of theplant and the operation thereof as a whole and the relationship betweenthe individual elements of the plant as well as the air flow and hot gasflow therein,

it is seen that the refuse 40, which is stored outside the plant, ispicked up periodically from time to time by means of a travelling crane42, or by a conveyor system (not shown) or any other suitable means, andfed in increments into the entrance to the plant 50, through a chute 52having diverging walls 54, 56 and a bottom which is connected to adrying chamber designated by number 100. Chamber 100 has positioned foroperation 6. therein a pair of drying grates 102, the details of whichwill be described later on under the heading Drying Grates.

In the following description, various number groups have been assignedto particular elements, to-wit: the plant itself and component structureare identified in the group between 50 and 99, all of the numbers in thegroup refer to drying grate parts, while the ignition grate chamber andignition grate structures are identified in the 200 and 300 group.

Leading from the incoming chute 52, there is a sand seal joint structureidentified generally as 58. The refuse 40, dumped through the chute 52,falls into the first chamber of the plant 50 which is a pro-dryingchamber 100 having drying grates 102 located therein. Refuse dropped ontop of the uppermost drying grate 102 is continuously circulated andmoved down the stair-step arrangement of the grates which arereciprocated by a power-driven connection means that will be describedlater. Following the pattern of FIG. 1, it is seen that the refuse iscarried down the upper and lower drying grates and dropped into theignition chamber 200 which has the ignition grates 202 located therein.For the time being, the details of the grates 202 will not be discussedand will be covered later on under the particular heading of IgnitionGrates.

The upper portion of the ignition chamber 200, represented by thenumeral 204, connects on one side with the drying chamber 100 andconnects to the rotary kiln 400 by a particular seal plate arrangement320. This seal 320 assures an air seal between the ignition grates 202and rotary kiln 400; and has arranged transversely thereacross a flatbafiie arch 206. In the pre-drying period, the refuse is pre-driedbeneath the feed chute as it is moved slowly by means of the movablegrates 102 toward the second or ignition chamber 200. The movable grates102 of the drying chamber 100 alternate between stationary grates, aswill be apparent hereinafter, and the arrangement includes twocontinually moving and reciprocating grate sections mounted on a slightangle with the horizontal to provide a downward movement and to cause atumbling action which gives the advantage of exposing all refuse surfaceto hot gases for pre-drying. In FIG. 1, as pointed out hereinbefore, thelight lines with arrowheads thereon and the indicia a, representgenerally the flow of air and gases throughout the plant, and it isnoted that the hot gases and air which flow from above the ignitiongrates 202 are directed back somewhat into the pre-drying chamber 100above the pre-drying grates 102, thereby aiding the drying of the refusepassing thereacross. The movement of these gases and this air from theignition grates 202 is aided measurably by the presence of the bafllearch 206 located above the ignition grates 202.

In conjunction with the ignition grates 202, in order to provide airwhich is necessary for good combustion of the refuse, there is suitableduct work 204 extending vertically in the building space below thedrying grates 102 and attached to the upper end of the ignition grates202 drawing primary air through a blower 210 and passing it by forcethrough the duct work 204 into the sides and beneath the ignition grates202, as will be more apparent hereinafter. It is this air from the ductwork 204 which passes under, then up through the ignition grates 202 andbed of refuse and across the ignition grates 202 thus mixing with thegases produced thereat and rising above the bed of refuse. Additionalair is taken off from the duct system and released over the burning bedof refuse by the over fired air system 205 on both sides of the chamber202 involving a particular arrangement of ignition assembly which willbe described later on. The refuse is moved along the ignition chamber byuse of the movable grate sections, which alternate between stationarygrate sections. The duct system 205 provides air over the refuse bed.The duct system is located on both sides of chamber 200 and the air flowis controlled by dampers.

The baffle arch 206 is constructed from suitable fire brick andstructural material over the ignition grate chamber and serves as adeflector to direct the hot gases over the bed of refuse on the dryinggrate.

The gases are then directed across the top of the bafile 206 and througha structural passageway 60 formed in the building structure into thechamber 500 to be described later on. Some gases from beneath the baflle206 pass up through a small passageway 62 and join in the chamberpassageway 60 with the gases passing therethrough. As the refuse passesacross the ignition grates 202, the grates are protected by a specialconstruction of the sidewall castings to protect the side walls 212 ofthe ignition chamber 200 from the burning of the refuse. In addition,the side wall castings 212 are protected from the heat of the chamber bythe forced draft air that passes back to them and cools the castings.The particular supports for the grates and the operation thereof,including a rocker arm method or a wear shoe method, will be describedlater.

From the ignition grates 202, whereon the refuse is constantly agitatedand turned downwardly, the burned material is dropped into the rotarykiln 400 for the remainder of the burning operation. The remainder ofthe burning of the refuse takes place within the kiln 400 and thedischarge end of the ignition chamber is protected from the heat bycastable refractory mounted on a discharge casting arrangement, thedetails of which will appear later. The hot gases that result from theburning of refuse in the ignition chamber 200 are utilized for predryingof the refuse in the drying chamber and are odorless in character. Tremove the odor from these gases, they are directed over the rotary kilnby the by-pass duct 60 which spills the gases into the chamber 500following the rotary kiln discharge end. This chamber 500 mixes thegases at a sufficient temperature to remove the odor from the hot gases.The mixing chamber 500 is so designed to cause turbulence by means ofthe bridge wall 506 within the chamber 500 and the offset wall 504 ofthe chamber according to a more detailed description to follow. Therefuse, as it is received by the rotary kiln 400, is tumbled to exposeall surfaces of the refuse to the hot gases and to complete the burningof the refuse. The rotary kiln is driven by a main drive gear whichmeshes with a girth gear mounted around the rotary kiln. The ash, as itis discharged from the end of the rotary kiln 400, is dumped into thediversion gate housing 502 which drops ash onto a diversion gate 508 andinto one of several residue conveyors. When properly installed andoperated, the incinerator unit or plant shall be capable of operatingentirely satisfactorily without manual stoking and shall produce a fine,completely consumed residue or ash.

Drying grate assembly Referring now to FIG. 2 for the details of thedrying grate assembly 102, the entire assembly is supported on aplurality of frame members 104 of I-beam construc tion or other suitableconstruction which are suitably supported on its own foundation withinthe building structure itself and held in place as by bolting or anyother conventional construction method. In the present embodiment, thereare two drying grates 102 supported on the frame members 104 foroperation thereon and each comprises a plurality of stair-step andside-by-side grates, movable grates 106 and stationary grates 108.Reference numbers 106, 108 constitute the entire assembly of movinggrate 106, stationary grate 108. They have subcomponents which will bedescribed in detail later.

Starting substantially in the center of the grate structure 102 in FIG.2, the center grate 106 is a movable grate, the next grate 108 is astationary grate and so on, alternating from one to the other to theoutside of the structure. The grate surfaces are plate-like members castin step formation as shown in FIGS. 2, 3, and 5. The movable grate 106has an elongated stringer 110 which supports different grate plates 109,111, 113. Stationary grates 108 are mounted on stringers 112. Grateplates 111 are affixed to stringers 110, 112 by means of lugs 116 whichare a part of the stringers 110, 112. These grate plates 111 lock to thestringers by the lugs 116. Grate plates 109, 113', being at the frontand rear ends of the stringers 110, 112, are affixed to the stringers bybolts 118 which fasten the plates to the stringers 110', 112.

Mounted on the frame 104 of the drying grate assembly 102 and extendingtransversely thereacross is a plurality of drive rollers or cylinders120 journaled on opposite ends in journals 122. A bell crank lever 124,driven by suitable motor drive (not shown), is connected by a connectingrod 126 with a second crank arm 128 attached to the uppermost drivecylinder 120 on one side of the frame. On the other side of the frame,drive cylinder 120 is connected with the next lower drive cylinder 120by means of a connecting rod 130. On that same side of the frame, an arm131 Ion the uppermost drive cylinder 120 of the lower grate set, whichis driven directly from the bell crank 124, is connected by suitablelinkage 132 to drive an arm 133 on the lowermost drive cylinder 120. Allof the drive cylinders 120 are adapted to drive the movable grates.Referring to FIG. 3, it may be seen that a pivot bracket assembly 134attaches each of the movable stringers 110 to a respective drivecylinder 120 and each of the stringers 110 is supported at an upper anda lower position on the drying frames.

The stationary grates 108 shown at the top of FIG. 3 are stationarilymounted by means of a notched bracket assembly 135 supported on atransverse beam 136 of the drying grate frame.

With the foregoing arrangement, power applied to reciprocate the bellcrank 124 is transferred to all of the drive cylinders 120 whichreciprocate the movable stringers, thereby moving the movable grates 106positioned thereon respective to the alternative rows of stationarygrates 108.

The lowermost end of the lower grates 106, 108 rest upon and aresupported upon an air cooled beam 140 of elongated box-like constructionand having a stepped upper surface 142 upon which is positioned anotched fastening wear-shoe member 144, on which the lower ends ofgrates 106 slide and the grates 108 rest. Member 144 is an elongatedwear pad bolted to the top of the air cooled beam 140 and has restingthereon all of the bottom edges of all of the moving grates 108. Thebottom of each of the movable grates 106 is bent underneath itself intoa ledge 146 which has attached thereto a wear pad plate 147 resting uponthe top of the lower drive cylinder 120. The front portion of theunderside of the grate 108 rests on the top of the wear pad 144 which isbolted to the air cooled beam 140.

Each of the movable stringers 110 are attached to the upper shaft 120 bymeans of the brackets 134 and each is provided on the sides thereof withwear pads 148 which bear against and slide against wear pads 150attached to each of the sides of the stationary stringers 112. All ofthese pads may be removed and replaced after they have Worn beyond useand Wear pads 148, 150 protect the stringers 110 and grates 106 fromwear and damage and protect the stringers 110 from Wear at the sidesthereof. According to this arrangement, only the wear pads 148, 150 arereplaced and the stringers 110 will provide considerably longer service.

The movable stringers 110 are supported upon a top drive roller shaft120 by means of the pivot bracket assembly mentioned previously. Thebracket assembly comprises a U-bolt 152 bolted with a cap block 154having slotted blocks 156 resting thereon. The bottom of each of themovable stringers 110 is H-shaped and it rests on the top of the cap 154and with the spaced block members 156 inside thereof. A pair of anchorpins 158 attach the slotted blocks 156 to the inside of stringers 110.Cap block 150 has a pivot pin 160 fitting into the slots in blocks 154.According to this arrangement, the drive shafts 120 reciprocate and thesupport between the block members 156 on the pivot pin 160 is a rockerconnection assembly which transfers the motion of the shaft 120 to rockor reciprocate the stringers 110, thereby moving the movable grates 110in an inclined play upwardly and downwardly substantially to the dottedline position shown in FIG. 3.

A wear shoe 162 on the bottom of the upper movable grate 120 wearsagainst a support beam 164 transversely fastened across the frame of thedrying grates between the upper drying grates and the lower dryinggrates. The movement of the lower drying grate 106 is against the wearshoe member 144 by the underside 146 and the wear shoe plate 148attached thereto.

The center portion of the drive shaft 120 is resisted from buckling bymeans of a support arrangement comprising a pair of rods 170 adjustablyfastened together by means of turnbuckles 172 and being attached betweenthe ends of the shaft 120 and the center of the shaft 120.

Ignition Grates The ignition grates structure is designated generally asNos. 200 and 202 in FIG. 1 and the particular ignition grate parts areall in the 200 and 300 series. It is noted, as described previously, inthe process in FIG. 1 that the refuse after being moved across thedrying grates 102 is directed by the drying grates 102 onto the upperentrance to the ignition grates 202, which in similar fashion to thedrying grates 102 move the refuse slowly down a stair-steppedarrangement, drying it across the top and under the bottom, at the sametime igniting and burning the refuse as it is moved down the incline.

The details of the ignition grates 202 are shown in FIGS. 10 through 19and this material will now be described. The ignition grate structure ismounted on a network of longitudinal beams 204 and vertical beams 206 ofthe heavy I-beam type welded or otherwise fastened together to form astructural support for the ignition grate structure 202 inside of theignition compartment 200. The support structure for the ignition grates200 is independent of the building and has its own foundation.

The entrance or elevated end 208 of the ignition grate structure iscovered by a vertical plate member 208 having opening 210 that serves asports whereby the siftings from the drying grates are collected in ahopper and conveyed back into the ignition chamber through these parts.

The siftings hopper is located in FIGURE 1, designated '600. Thisrecharging system provides for the continual re-entry of all thesittings from under the drying grates 100 into the ignition chamber 200therein. The sidewalls of the grate structure (as seen also in thecrosssectional view in FIG. 18) are composed of a plurality of removableand replaceable grate sidewall castings or casting plates 212, whichtogether with an exterior steel plate Wall 214, attached on the outsideof the ignition grate structure, form a chamber.

Referring to FIGS. and 16, each casting or plate 212 has an upper lug orprotrusion 216 with a tip 218 fitting about the inner upper edge of theinterior projection 220 of the outer wall 214. Optionally, auxiliarysupport members 221 attached on top of casting 212 on protrusion 216 andover projection 220 (see FIG. 16) provides a base support for anyrefractory material of the ignition chamber used to cover and protectthe sides. Bottom plates 212 have an upper projection 222 fitting insideof the upper plate 212 and closing the gap therebetween. The bottom ofthe bottom casting 212 fits into the inner end of the outer wall 214 andrests upon a longitudinal structure support 223 fastened to the beams204, 206 of the over-all grate support structure.

With this arrangement, the upper or lower sidewall castings 212 may beremoved individually and replaced when unduly worn. Side wall castingpiece 224 is a casting that allows for the adjustments between the sidewall castings 212 and the grates. The very smooth, finished surface ofcastings 212 against which the refuse passes as it is moved downwardlyacross the ignition grates assures a more positive and smooth flow ofthe burning refuse preventing most of the large clinkering which hasoccurred in other types of ignition arrangements. Each sidewall casting212 is provided with a plurality of normally sealed bolt openings 225closed by bolts anchoring the side wall castings 212 to wall 214.

Both sidewalls of the ignition grate structure are provided with anelongated duct 226 extending from an opening in the front plate 208downwardly along and against and communicating with the sidewall castingstructure on that side and having an auxiliary duct 228 extendingdownwardly and terminating with an opening adjacent the underside of theignition grate structure beneath the support beams 204. According tothis arrangement, the mouth or terminal opening of the duct 228 exhaustsair beneath the ignition grates, thereby supplying air that passes upthrough the grates, thus providing air for the combustion.

The ducts 226, 228 are provided with a damper 229 which may be used tocontrol the volume of the air flowing therethrough. The front, ordownward end, 230 of the ignition grate structure 202 is constructed ina particularly unique and advantageous manner. Member 230 is an endplate for the side wall duct work. Plate 234 is a semi-circular platethat forms an interconnecting seal with the rotary kiln 400 and theignition grate 200.

The semi-circular portion 231 has attached to the bottom thereof abottom plate 232 formed with a seam in the center thereof and beingbolted to the two semicircular fianges 234 attached thereto. Thedischarge castings 236 are flat metal plates and as seen in thecrosssectional view in FIG. 16, each of these plates is bolted to aninside facing 238 attached rigidly on the frame of the ignition grate.Accordingly, the top portion 239 and the main body of discharge castings236 may be removed from the front of the ignition grates and replacedafter they have received the maximum wear.

The ignition grates themselves are designated generally by the numerals240 and 242 representing, respectively, the stationary grates and themovable grates arranged similar to the drying grates describedpreviously. As is readily seen in FIG. 12, the movable grate structure242 comprises an elongated stringer 244 of beam-like construction havinga plurality of spaced bolt holes 246 formed in the upper surface thereofinto which are fitted the spacer bars 248 on which fits a lug 250 of abasket casting member 251, each of stepped construction and having afront end overlapping the rear end of a succeeding lower basket member.All of the basket members 251 are removable individually from thestringer 244 so that they may be replaced when worn, broken or otherwiseunserviceable. Each basket 251 has two sides and supports thereonignition grate bars 253. Each stringer 244 is adjacent to a stationarygrate 240 supporting stationary grate bars 254 in identical fashion tothe arrangement shown in the preceding drying grates. The movableignition grates 242 and stringer 244 are rockermounted for movement onthe frame structure 206 by a rocker-mounting arrangement 258 now to bedescribed.

Rocker-mounting arrangement 258 is mounted upon a support 260 attachedto a cross I beam 262 on the frame 206 and comprises a support armarrangement shown in detail in FIG. 12. An arm or upstanding member 264has a ball 266 attached on each end thereof which fits into a socketarrangement 267 contained on the support 260 and attached on an uppersupport member 268 attached beneath and to the stringer member 244. Anidentical construction is found in both the upper end and the lower endof the stringer member 244, there being at least two of therocker-mountings 258 supporting each stringer 244.

The drive assembly 270 for all of the movable stringers 244 and ignitiongrates 242 is shown clearly in FIGS. 11 and 12 and comprises a drive arm272, which receives power from a drive cylinder and piston arrangement(not shown) or any source of power. Drive arm 272 has a crank 274pivotally attached thereto which reciprocates to translate motion in aforwardly and rearwardly direction to drive a shaft 276 supported onbearings 278 on the ignition grate frame structure 204, 206. Shaft 276has attached thereon a pair of drive bracket members 280, there beingone pair for each of the movable ignition grates 242. Each pair ofbrackets 280 has a connecting arm 282 attached pivotally by a pivot pinand is attached to the movable stringer 244 by means of a pin and eyearrangement 283. A sleeve 284 is keyed to shaft 276 and is pivotallyattached to the bracket 280 by a shear pin 285.

According to the drive arrangement 270, each movable stringer 244 withthe grates 250 mounted thereon, is driven independently of all of theothers by means of the independent drive bracket 280 and shear pin anddrive arm arrangement 285 which connects the drive shaft 276 with arespective stringer 244. Therefore, if for any reason, any stringer 244should become disabled or jammed or otherwise inoperative, it wouldeither cease to function or would shear its own individual shear pin285, permitting the remainder of the movable stringers 244 to functionnormally. At some time a bro-ken shear pin 285 can be replaced and thesource of the trouble can be located and corrected. Each movablestringer 244 and the ignition grates 250 are provided with a particulararrangement of wear shoes and wear means to absorb the wear and thiswill now be described.

An alternative and modified form of support for the stringer 244 isshown by FIGS. 17 and 18 as a wear shoe support 285. Each movingstringer 244 has attached on the underside thereof a bracket 286 whichis pivotally attached by a pivot pin 288 to a flat, elongated wear shoe290 having downturned edges 292 thereon which fit over a support block294. Support block 294 has a depending lug 295 thereon which fits in apair of protruding lugs 296 attached to a support plate 297 bolted toanother plate 298, which is welded to a channel 299 attached on thebottom of the support frame 204, 206 of the ignition grate structure.Plate 297 is bolted to plate 298 by a pair of bolts 300 fitting inelongated slots on the plate 297.

A projecting plate 302 welded to the channel 299 has a pair ofadjustment bolts 304 placed therein which engage and bear against aprojecting portion of the plate 297 whereby adjustment pressure may beapplied to the entire plate structure 297 in order to adjust theinclination thereof at the same time or independently of adjusting theposition of plate 297 with respect to 298 so as to cause an alignmentand an adjustment to compensate for the wear which has taken placebetween the wear shoe 290 and the support block 294.

Since the elongated stringer 244 is pivotally attached on the elongatedwear shoe 290 which slottably fits over support block 294, thereciprocating movement of the beam 244 is transferred to the top of theblock 294 by the sliding shoe 290 and the friction wear takes place atthis point. Compensation is made for this from time to time by adjustingthe bolts 300, the adjustment screws 304 by virtue of all of which theshoe 290 may be brought into firmer contact with the block 294.

In the modified form of support for the stringers 244 shown in FIG. 17,each stringer 244 has attached at the top underside thereof a bracket320 to which is attached the bolt and nut fastener 322 on one end of awire rope holddown member 324 attached by a second bolt and nut fastener322 with one of the cross-frame members 206 of the ignition gratesupport structure. When the stringer 244 and grate structure thereon, isin its uppermost position of sliding on wear supports 285 the cableholddown member 324 is not under much tension but the tension thereonincreases as the stringer moves downwardly thereby pulling downwardly onthe top of the stringer 244 preventing it from rising appreciably. Inother words, the stringer 244 is held to travel as much as possible in astraight line.

While we have shown and described a particular embodiment of ourinvention and a particular description of the method and apparatusemployed in the instant incinerator, this is but one form of ourinvention having typical characteristics and being for descriptivepurposes mainly and is not to be construed as any sort of limitation onthe scope of our invention, since various alterations, substitutions,changes, eliminations, revisions, and modifications may be made in theembodiment shown and described and in the method presented withoutdeparting from the scope of our invention set forth in the appendedclaims.

We claim:

1. In a drive means for drying grate structure to be employed in anincinerator plant wherein refuse is being delivered continuously from aninput onto said drying grates, a drying grate structure including anelongated drying grate having upper and lower sections, said dryinggrate comprising stationary grates alternating between reciprocating,movable grates, each of said grates having castings thereon, atransverse drive shaft attached on said drying grate, a bracket for eachof said movable grates attached to said drive shaft, pivot meansconnecting said bracket with said movable grates on each of said upperand lower sections, and a shear pin in said bracket connecting saidbracket to said drive shaft, whereby said movable grates arereciprocated between said stationary grates and said individual shearpins will break if one of said grates is prevented from movement therebypermitting the rest to move.

2. A replaceable ignition grate structure for a continuous incineratorprocess wherein pre-dried refuse is delivered onto the ignition grateswhereat it is circulated from top to bottom and ignited as it passesthereacross, comprising: an ignition grate structure including anignition grate frame adapted to be mounted independently of theremainder of any continuous process system, said ignition grate framecomprising vertical and transverse support beams, said ignition gratecomprising a plurality of stationary and moveable ignition gratesdisposed in side by side relationship, an elongated stringer ofbeam-like construction supporting each of said ignition grates, basketcasting members on said grates and each having a spacer bar, saidstringer having'a plurality of holes therein into which are fitted thespacer bars of said basket casting members, each of said basket castingmembers being of stepped construction and having a front end overlappingthe rear end of a succeeding lower basket casting member, and all ofsaid basket casting members being removable from said stringer so thatthey may be replaced when worn.

3. In a drying grate structure for a continuous process incineratorwherein refuse is continuously being moved from the input portion of theincinerator toward the final disposition thereof, a frame, a dryinggrate structure including movable drying grates arranged in side-by-siderelationship alternating with stationary grates, each of said gratesbeing an independent member mounted upon said frame, said stationarygrates resting on said frames, a drive means on said frame connected tosaid movable grates, a pivot means connecting said drive means to saidmovable grates and by which said movable grate pivots as said grate ismoved back and forth, and a wear pad on the under side of the end ofsaid movable grates and a complementary wear pad mounted on the memberupon which said grate wear pad rubs as said grate moves back 13' andforth, said wear pads being removable to be replaced after they haveworn beyond use.

4. In a drying grate structure for a continuous process incineratorwherein refuse is continuously being moved from the input portion of theincinerator toward the final disposition thereof, movable drying gratesand stationary grates arranged in alternating side-by-side relationship,each of said grates being an independent member mounted upon said framegrate drive means for said movable drying grates, said movable gratesbeing driven by said grate drive means on said structure back and forth,an air cooled beam upon which rests the front portion of the undersideof said stationary grates, a wear pad on the under side of the end ofsaid movable grates and a complementary wear pad mounted on said gratedrive means upon which said grate wear pad rubs as said grate movesback-and-forth, said wear pads being removable to be replaced after theyhave worn beyond use.

5. In a drying grate structure for a continuous process incineratorwherein refuse is continuously being moved from the input portion of theincinerator toward the final disposition thereof, a frame, a pluralityof individual drive shafts journalled transversely across said frame forrocking motion thereon, rocker arm means connecting said drive shaftsfor rocking same, power means for driving said rocker arm means, adrying grate structure including an upper drying grate structure and alower drying grate stucture on said fame, each of said drying gratestructures comprising a series of stationary drying grates and movabledrying grates arranged in side-by-side relationship alternating from amoving to a stationary grate, each of said grate members being anindependent member, a separate stringer on said frame mounting arespective grate member, a transverse member on said frame, saidstationary grates being attached to said frame, a pivot means connectingsaid movable grates to one of said drive shafts.

6. In a drying grate structure for a continuous process incineratorwherein refuse is continuously being moved from the input portion of theincinerator toward the final disposition thereof, a frame, drive meanstransversely across said frame for rocking motion thereon, meansconnecting said drive means for rocking same, power means for drivingsaid connecting means, a drying grate struc ture including an upperdrying grate structure and a lower drying grate structure on said frame,each of said drying grate structures comprising a series of stationarydrying grates and movable drying grates arranged in side-by-siderelationship alternating from a moving to a stationary grate, stringerson said frame, each of said drying grates being an independent membermounted upon a separate stringer on said frame, said stationary gratesattached on said frame, .pivot means pivotally supporting said movablegrates, said movable grate pivoting as said grate is movedback-and-forth, and a wear pad on the under side of the end of saidmovable grates and a complementary wear pad mounted on the lowermostsupport upon which said grate wear pad rubs as said grate moves back andforth, said wear pads being removable to be replaced after they haveworn beyond use.

7. In a drying grate structure for a continuous process incineratorwherein refuse is continuously moved from the input .portion of theincinerator toward the final disposition thereof, a frame, a pluralityof individual drive shafts journalled transversely across said frame forrocking motion thereon, rocker arm means connecting said drive shaftsfor rocking same, power means for driving said rocker arm means, adrying grate structure including an upper drying grate structure and alower drying grate structure on said frame, each of said drying gratestructures comprising a series of stationary drying grates and movabledrying grates arranged 'in side-by-side relationship alternating from amoving to a stationary grate, a plurality of separate stringers on saidframe, each of said grates being an independent member mounted upon aseparate stringer on said frame, transverse member on said frame, saidstationary grates having a notch bracket on one end thereof fitting overa transverse member on said frame, brackets on said frame, said movablegrates being connected by a bracket to one of said drive shafts, a pinin said bracket upon which pin said stringer of said movable grate restsas said grate is moved back and forth, an air cooled beam upon whichrests the front portion of the underside of said lower stationarygrates, a wear pad on the under side of the end of said movable gratesand a complementary wear pad mounted on the lowermost drive shaft uponwhich said grate wear pad rubs as said grate moves back and forth, saidwear pads being removable to be replaced after they have worn beyonduse.

8. In an ignition grate structure for an incinerator adapted toincinerate refuse in a continuous manner as it flows through acontinuous process, a frame, an ignition grate structure, a plurality ofignition grate stringers mounted on said frame, said stringers includingmovable stringers and stationary stringers, movable ignition grates andstationary ignition grates supported on said stringers, movable gratecastings removably mounted upon said movable stringers, stationary gratecastings mounted upon said stationary stringers adjacent to said movablegrate castings, wear pads on said ignition grates between said adjacentstringers absorbing the motion therebetween, and a drive means for saidmovable stringers comprising a drive shaft on said ignition gratestructure, individual drive connecting members attached to said driveshaft and to a respective movable stringer, a shear pin in saidconnecting member for each of said movable stringers whereby saidstringers are driven independently of one another and the individualshear pin will break if one of said stringers is retarded from propermotion and without affecting the movement of the other stringers.

9. In an ignition grate structure for an incinerator adapted toincinerate refuse in a continuous manner as it flows through acontinuous process, a frame, an ignition gr-ate frame structure, aplurality of ignition grate stringers mounted on said frame, saidstringers including movable stringers and stationary stringers, movableignition grates and stationary ignition grates supported on saidstringers adrive means for said movable stringers comprising atransverse drive shaft across the end of said ignition grate structure,individual drive connecting rods pivotally attached to said drive shaftand to a respective movable stringer, a shear pin in said connecting rodfor each of said movable stringers whereby said stringers are drivenindependently of one another and the individual shear pin will break ifone of said stringers is retarded from proper motion and Withoutaffecting the movement of the other stringers.

10. In an ignition grate structure for an incinerator plant, a pluralityof stair-step and side-by-side ignition grates, there being movablegrates and stationary grates, an elongated stringer supporting each ofsaid ignition grates, basket casting members having spacer bars, saidstringer having a plurality of holes therein into which are fitted thespacer bars of a basket casting member, each of said casting membersbeing of stepped construc tion and having a front end overlapping therear end of a succeeding lower basket members, means to removably mountall of said basket members from said stringers so that they may bereplaced when worn, a shock mounting and power drive for said movablestringers comprising a ball joint on said stringer and a ball joint onsaid frame, a support arm connecting said ball joints, a drive means forsaid stringer comprising a transverse drive shaft on said frame, powermeans for said drive shaft, crank means driving said drive shaft toreciprocate same, and means drivably connecting each of said movablestringers with said drive shaft whereby said stringers are reciprocatedby said shaft.

11. An ignition grate structure for a continuous incinerator processwherein pre-dried refuse is delivered onto the ignition grates whereatit is circulated from top to bottom and ignited as it passesthereacross, comprising: an ignition grate structure including ignitiongrates and an ignition grate frame adapted to be mounted independentlyof the remainder of any continuous process system and comprisingvertical and transverse support beams, a plurality of side-by-side,stairstep grates, there being stationary grates and movable grates onsaid frame, an entrance at the top leading onto said ignition grates andhaving an opening therein adapted to receive material from the previousprocess, sidewalls on said ignition grate extending from said grateframe above the-elevation of said ignition grates, sidewall castings onsaid sidewall, and an inlet on the front of said ignition grate, ductmeans on said sidewalls of said ignition grates extending from the inletin the front downwardly along and against and communicating with thesidewall castings on that side, an open duct communicating with saidduct means and being open beneath said ignition grates whereby air isexhausted therebeneath.

12. An ignition grate structure for a continuous incinerator processwherein pre-dried refuse is delivered onto the ignition grates whereatit is circulated from top to bottom and ignited as it passesthereacross, comprising: an ignition grate structure having ignitiongrates and an ignition grate frame adapted to be mounted independentlyof the remainder of any continuous process system and comprisingvertical and transverse support members, a plurality of side-by-sidegrates, there being stationary grates and movable grates on said frame,an entrance on said ignition grates at the top thereof and having anopening therein adapted to receive siftings from the previous dryingprocess, an elongated stringer of beam-like construction supporting eachof said ignition grates, a wear shoe on each of said stringers, asupport block for said wear shoe on said frame, means for adjusting eachwear shoe, a drive means for said stringer comprising a drive shaft onsaid frame, power means for said drive shaft, a drive member for each ofsaid movable ignition grates, and each of said drive members having adrive connection attached thereto attaching said shaft to a movablestringer.

13. An ignition grate structure for a continuous incinerator processwherein pre-dried refuse is delivered onto the ignition grates whereatit is circulated from top to bottom and ignited as it passesthereacross, comprising: an ignition grate structure having ignitiongrates and an ignition grate frame adapted to be mounted independentlyof the remainder of any continuous process system and comprisingvertical and transverse support beams, a plurality of side-by-sidegrates, there being stationary ignition grates and movable ignitiongrates on said frame, a covered entrance on said ignition grates at thetop thereof and having an opening therein adapted to receive siftingsfrom the previous drying process, sidewalls on said ignition grateextending from said grate frame above the elevation of said ignitiongrates, each of said sidewalls being composed of a plurality ofremovable and replaceable grate sidewall casting plates and each of saidcasting plates comprising a substantially flat plate with a smooth,outer surface thereon, each of said plates having an upper lug thereonwith a tip fitting about the inner edge of the outer wall whereby saidgrates may be removed and replaced, an inlet on the front of saidignition grates, duct means on said sidewalls on said ignition gratesextending from the inlet in the front downwardly along and against andcommunicating with the sidewall castings on that side, said duct meansterminating with an open duct extending beneath said ig;

nition grates whereby air is exhausted therebeneath, an

elongated stringer of beam-like construction supporting each of saidignition grates, basket casting members having spacer bars, saidstringer having a plurality of holes therein into which are fitted thespacer bars of the basket casting member, each of said basket castingmembers being of stepped construction and having a front end overlappingthe rear end of a succeeding lower basket members, and all of saidbasket members being removable from said stringers so that they may bereplaced when worn, a shock mounting and power drive for said movablestringers comprising a ball joint on said stringer and a ball joint onsaid frame, a support arm connecting said ball joints, a drive means forsaid stringer comprising a transverse drive shaft on said frame, powermeans for said drive shaft, crank means driving said drive shaft toreciprocate same, a plurality of independent bracket members, therebeing one for each of said movable ignition grates, pivot means for eachbracket member, a connecting arm, each of said bracket members attachingsaid bracket to a movable stringer, a sleeve on said shaft at eachbracket member, and a shear pin pivotally attaching said sleeve to saidbracket member.

14. In a wear shoe support for a movable grate structure supported onthe grate frame of an incinerator wherein refuse is moved continuouslyduring incineration, comprising: a movable grate structure, a grateframe supporting said movable grate structure, a wear shoe supportbracket on said movable grate structure, a wear shoe attached on saidbracket, a depending lug on said shoe, a support plate having a pair oflugs thereon into which is fitted said depending lug, a second platefixed on said grate frame, said second plate having adjustment aperturesformed therein, bolt means attaching said support plate on said secondplate, a projecting plate fixed on said frame, and adjustment means onsaid projecting plate acting on said support plate to adjust theposition of same, said bolt means being loosened to effect saidadjustment.

References Cited by the Examiner UNITED STATES PATENTS 1,211,755 1/17Reagan 38 1,393,979 10/21 Skelly 110-38 1,947,831 2/34 Davidson 1l0382,015,842 10/35 Christensen 11015 X 2,037,990 4/36 Martin 1101652,122,314 6/ 38 Fields 11018 2,167,653 8/39 Holbrook et al. 1 10--182,269,273 1/42' Krogh et al. 1108 2,402,906 6/46 Mosshart 12237 62,431,415 11/47 Mosshart 110-38 2,589,836 3/52 Martin 110165 2,809,02410/57 Simon et al 263-32 2,879,862 3/59 Burden.- 1 836 2,904,322 9/5-9Bruit 26332 2,906,368 9/59 Nelson l-83-6 2,960,943 11/60 Andersen 110-15 3,016,849 1/62 Markle et al. 11038 3,04'2,3 89 7/62 Gieshieng 110-143,046,915 7/62 Ludin 110-15 3,055,320 9/62 Bolda 1l015 FOREIGN PATENTS586,872 4/47 Great Britain.

FREDERICK L. MATTESON, JR., Primary Examiner.

PERCY L. PATRICK, FREDERICK KETTERER,

JAMES W, WESTI-IAVER, Examiners,

1. IN A DRIVE MEANS FOR DRYING GATE STRUCTURE TO BE EMPLOYED IN ANINCINERATOR PLANT WHEREIN REFUSE IS BEING DELIVERED CONTINUOUSLY FROM ANINPUT ONTO SAID DRYING GRATES, A DRYING GRATE STRUCTURE INCLUDING ANELONGATED DRYING GATE HAVING UPPER AND LOWER SECTIONS, SAID DRYING GRATECOMPRISING STATIONARY GRATES ALTERNATING BETWEEN RECIPROCATING, MOVABLEGRATES, EACH OF SAID GRATES HAVING CASTINGS THEREON, A TRANSVERSE DRIVESHAFT ATTACHED ON SAID DRYING GRATE, A BRACKET FOR EACH OF SAID MOVABLEGRATES ATTACHED TO SAID DRIVE SHAFT, PIVOT MEANS CONNECTING SAID BRACKETWITH SAID MOVABLE GRATES ON EACH OF SAID UPPER AND LOWER SECTIONS, AND ASHEAR PIN IN SAID BRACKET CONNECTING SAID BRACKET TO SAID DRIVE SHAFT,WHEREBY SAID MOVABLE GRATES ARE RECIPROCATED BETWEEN SAID STATIONARYGRATES AND SAID INDIVIDUAL SHEAR PINS WILL BREAK IF ONE OF SAID GRATESIS PREVENTED FROM MOVEMENT THEREBY PERMITTING THE REST TO MOVE.